One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of making a decision about when you can plant thunbergia is to use the USDA zone info for Campbell.

Planting Calendar for Thunbergia

Frost tolerance for thunbergia:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

You should not plant thunbergia until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant thunbergia in Campbell is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant thunbergia and expect a good harvest is probably August. You probably don't want to wait any later than that or else your thunbergia may not have a chance to really do well. You can get started a little bit earlier by starting your thunbergia indoors.

Last Frost Date

In Campbell the average date of last frost happens on April 15. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Campbell is just an average the actual date of last frost will vary from year to year. Since half of the time in Campbell there is a last frost after April 15 be ready to protect your thunbergia if you have a late frost.

USDA Zone Info for Campbell

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Campbell

You may be interested in your other planting guides for Campbell.